Research progress of “rocking chair” type zinc-ion batteries with zinc metal-free anodes

“Rocking chair” type lithium-ion batteries with lithium metal-free anodes have been successfully commercialized over the past few decades. Zinc-ion batteries (ZIBs) have gained increasing attention in recent years given their safety, greenness, ease of manufacture, and cost-efficiency. Nevertheless, the practical application of ZIBs is largely hindered by the dendritic growth of the Zn metal anode, low Coulombic efficiency, great harm, and existence of various side reactions. Herein, this review provides a systematic overview of emerging “rocking chair” type ZIBs with zinc metal-free anodes. Firstly, the basic fundamentals, advantages, and challenges of “rocking chair” type ZIBs are introduced. Subsequently, an overview of the design principles and recent progress of “rocking chair” type ZIBs with zinc metal-free anodes are presented. Finally, the key challenges and perspectives for future advancement of “rocking chair” type ZIBs with zinc metal-free anodes are proposed. This review is anticipated to attracted increased focus to metal-free anodes “rocking chair” type metal-ion battery and provide new inspirations for the development of high-energy metal-ion batteries.